Device and method for dosing cooling medium for the purpose of cooling drinks

ABSTRACT

The invention relates to a device for dosing a cooling medium, in particular for the purpose of cooling drinks. The device comprises at least one cooling medium supply container ( 4 ) for holding at least one liquid cooling medium with a boiling point lower than room temperature, at least one dosing element ( 7 ) connected to the cooling medium supply container via at least one supply conduit for the purpose of dosing a quantity of liquid cooling medium, in particular for cooling a drink by being mixed with the- drink, and at least return conduit ( 8 ) connected to the cooling medium supply container for cooling with substantially liquid cooling medium the supply conduit ( 6 ) provided with cooling medium.

PRIORITY CLAIM

The present application is a national phase application filed pursuantto 35 USC §371 of International Patent Application No.PCT/NL2009/050472, filed 30 Jul. 2009, which application claims thebenefit of Dutch Patent Application No. 2001874, filed 4 Aug. 2008; allof the foregoing applications are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The invention relates to a device for dosing a cooling medium, inparticular for the purpose of cooling drinks. The invention also relatesto a dosing element for use in such a device. In addition, the inventionrelates to an assembly for use in a device according to the invention.The invention further relates to a method for dosing a cooling medium,in particular for the purpose of cooling drinks, making use of such adevice.

BACKGROUND

Machine preparation of milkshakes generally takes place by arranging awater-comprising basic substance in a freezing cylinder. A fraction ofthe basic substance positioned close to the wall of the freezingcylinder will herein (partially) freeze. The actual cooled milkshake canbe obtained by scraping the frozen fraction from the wall of thefreezing cylinder, crushing and subsequently mixing it with the unfrozenfraction of the basic substance. The milkshake will generally also beaerated to provide the milkshake with a lighter character. Although thismethod is applied industrially on a large-scale in the market, thismethod for preparing, and in particular cooling, milkshakes has a numberof drawbacks. A significant drawback of the known method is that arelatively large number of moving components, such as a scraper andbreaking means for crushing the frozen fraction, are required to enablepreparation of the milkshake, and this makes the preparation methodrelatively time-consuming. Furthermore, the equipment required to applythe known preparation method, provided with the scraper and the breakingmeans, is relatively complex and requires relatively frequentmaintenance, and is therefore relatively expensive.

SUMMARY

A solution to the above stated problems is described in non-publishedinternational patent application PCT/NL2008/050068. This patentapplication describes a device for cooling drinks, using which device adrink, such as a milkshake, can be cooled quickly and effectively bymixing the drink with a dosed quantity of liquid cryogenic coolingmedium, in particular liquid nitrogen. In order to be able to preventinstantaneous freezing of the drink a vortex is applied to the drink bymeans of stirring while the cooling medium is being added to the drink.In addition to the method of adding the cryogenic cooling medium to thedrink, the method of dosing the cooling medium before it is added to thedrink for cooling also forms a critical process. Too small a quantity ofthe cooling medium would result in an unsatisfactory cooling of thedrink. Too large a quantity of the cooling medium would result infreezing of at least a substantial part of the drink, this also beingundesirable. The dosing of the cooling medium is made more difficult inthat the (cryogenic) cooling medium that is kept liquid has a boilingpoint below room temperature (20° C.). This means that the coolingmedium will tend to evaporate in the device before the cooling medium isdispensed by the device. Since the dosing generally takes place intime-controlled manner, wherein a dispensing opening is opened for apredetermined period of time, formation of gas in the device willconsiderably impede a precise dosing of the cooling medium.

The invention has for its object to provide a device enabling relativelyprecise dosing of cooling medium for the purpose of cooling drinks.

The invention provides for this purpose a device of the type stated inthe preamble, comprising: at least one cooling medium supply containerfor holding at least one liquid cooling medium with a boiling pointlower than room temperature, at least one dosing element connected tothe cooling medium supply container via at least one supply conduit forthe purpose of dosing a quantity of liquid cooling medium for cooling adrink by being mixed with the drink, and at least one cooling conduitconnected to the cooling medium supply container for cooling withcooling medium the supply conduit provided with cooling medium. Thecooling medium guided through the cooling conduit will generally besubstantially liquid in nature, although it can also form a mixture ofat least liquid cooling medium and gaseous cooling medium. Particularlyduring a start-up phase of the device a gas fraction will generally bepresent in the cooling conduit, and in the operative situation, in whichcooling medium is actually dosed via the at least one dosing element,the cooling medium guided through the cooling conduit will generally besubstantially or even wholly liquid to enable the cooling medium guidedthrough the supply conduit to be held at temperature in relativelyefficient manner. Not only a gaseous cooling medium will be guidedthrough the cooling conduit in the operative situation, since thecooling capacity of a gaseous cooling medium is substantially lower, andusually too low, than in the case that an at least partially andpreferably substantially liquid cooling medium is guided through thecooling conduit. By cooling the cooling medium present in the supplyconduit using the cooling conduit likewise provided with cooling medium,formation of gas in the supply conduit can be prevented in relativelyefficient and effective manner, which considerably facilitates precise,in particular time-controlled, dosing of cooling medium manner for thepurpose of cooling drinks and moreover makes it reproducible andtherefore more reliable. The cooling of cooling medium present in thesupply conduit using cooling medium present in the cooling conduit isparticularly efficient because only one cooling medium is required. Thephysical properties of the cooling medium present in the supply conduitand the cooling medium present in the cooling conduit are moreoveridentical, whereby sufficient cooling of the cooling medium present inthe supply conduit can be realized in relatively simple manner. Thecooling medium moreover comes from a single cooling medium supplycontainer, whereby it is not necessary to apply a separate supplycontainer, whereby the device as such can be embodied with a relativelysimple construction. The use of a separate cooling conduit to insulatethe supply conduit relative to the atmosphere in order to preventwarming of the cooling conduit as far as possible is substantiallycheaper, and therefore more efficient, than if for instancevacuum-insulated conduits were to be used. The device is particularlysuitable for dosing relatively cold (cryogenic) liquid cooling mediawith a boiling point (substantially) lower than room temperature (atatmospheric pressure), since the supply conduit is at least partlyinsulated by the cooling conduit, whereby evaporation of cooling mediumin the supply conduit is prevented. A significant advantage of suchtypical cryogenic cooling media compared to non-cryogenic cooling media,such as for instance cold water, is that the cryogenic cooling mediahave a great cooling capacity, whereby only a limited quantity ofcooling medium is required to enable a rapid and effective cooling ofthe drink to be realized. Liquid nitrogen is preferably applied ascooling medium, since liquid nitrogen is relatively inexpensive andnon-toxic. Furthermore, nitrogen need not necessarily be preserved in apressure vessel. It is possible to envisage preserving nitrogen underatmospheric pressure in the cooling medium supply container. In additionto nitrogen, it is also possible to envisage applying for instanceliquified air, liquified carbon dioxide and liquid helium. It is alsopossible to envisage applying other types of cooling medium, generallyprovided however that the cooling medium is suitable for consumption bya consumer. Various beverages can be cooled using the device accordingto the invention, including milkshakes, alcoholic (mixed) drinks, iceddrinks, in particular slush puppies, fruit drinks, in particularsmoothies, soft drinks, yoghurt, quark cheese, soups and water. It ishowever also possible to cool soft ice-cream using the device accordingto the invention. Soft ice-cream is therefore also deemed to be a drinkwithin the context of this patent publication. During the cooling of thedrink the heat required for heating and evaporating the liquid coolingmedium will be extracted from the drink for cooling, whereby the coolingof the drink will be realized. It is also possible here to envisage icecrystals forming in the drink, which can contribute toward the tastesensation of the cooled drink. The drink will moreover be aerated by theevaporation of the cooling medium. Depending on the nature of the drink,and particularly the viscosity of the drink, the gas bubbles will remainenclosed in the drink in relatively stable and sustained manner or beable to escape relatively quickly and easily from the drink. In additionto the use for cooling drinks, it is also possible to envisage thedevice according to the invention being applied in other types ofapplication, in which dosing of particular cooling media is desired.

In a preferred embodiment the cooling conduit, or at least the coolingmedium received therein, connects directly to an outer wall of thesupply conduit, whereby heat absorption by the supply conduit can beprevented as far as possible, which helps to maintain the temperature ofthe supply conduit. The cooling conduit preferably encloses the supplyconduit at least partially. The at least one cooling conduit morepreferably encloses an outer wall of the supply conduit substantiallyall the way round. In the case that a plurality of cooling conduits areapplied it is possible to envisage one cooling conduit covering a partof a peripheral wall of the supply conduit while one or more othercooling conduits cover a remaining part of the peripheral wall of thesupply conduit. In this way heating of the supply conduit and thecooling medium present therein, and thereby formation of gas in thesupply conduit, can be prevented as far as possible. In a particularpreferred embodiment at least a part of the cooling conduit and at leasta part of the supply conduit are oriented coaxially with each other,wherein an inner conduit is formed by the supply conduit and an outerconduit is formed by a cooling conduit.

The supply conduit and the cooling conduit can respectively form part ofseparate cooling medium circuits. In general however, it is particularlyadvantageous if the cooling conduit is formed by a return conduitconnected to the supply conduit for the purpose of returning via thecooling conduit cooling medium guided through the supply conduit. Inthis way a single cooling medium circuit is used, which is applied onthe one hand to enable dosage of a quantity of cooling medium for thepurpose of cooling a drink and which is applied on the other hand tocool the supply conduit so as to be able to prevent formation of gas inthe supply conduit and to be able to ensure a reliable dosing of thecooling medium. The return conduit is preferably connected to the supplyconduit via the dosing element. In this way a maximum length of thesupply conduit can be cooled by the return conduit, which enhances theinsulating action of the return conduit. The dosing element can moreoverbe applied here as control valve for causing return of cooling mediumvia the return conduit or for causing dispensing of a dosed quantity ofcooling medium via a dispensing opening of the dosing element for thepurpose of cooling a drink. In a particular preferred embodiment thesupply conduit and the return conduit connect to a dosing compartmentforming part of the dosing element. The dosing compartment is in factformed by a collection chamber for cooling medium to which the at leastone supply conduit, the at least one return conduit and the at least onedispensing opening are connected. The dosing element more preferablycomprises here at least one controllable closing element for closing thedispensing opening of the supply conduit. The closing element canoptionally also be adapted to be able to close the return conduit. Theclosing element thus functions as said control valve in the dosingelement. Since a cryogenic cooling medium with a boiling point(substantially) lower than room temperature is applied, the temperatureof the liquid cooling medium will generally be low. Liquid nitrogen thushas a temperature of −196° C. These relatively low temperatures aregenerally unsuitable for the application of an electromechanicaloperating element to enable operation of the closing element. It istherefore recommended that the closing element is connected to anoperating element via at least one spacer for the purpose of enablingoperation of the closing element at a distance from the closing element.In this way the operating element can be positioned outside therelatively cold zone of the dosing element, which will in generalsignificantly enhance the reliability of the operation of the closingelement. The spacer is here generally formed by a rod. The operatingelement can for instance be formed by a magnet, which magnet is adaptedto co-act with a controllable electromagnet forming part of the dosingelement. The parts of the dosing element situated in the cold zone, i.e.the zone which is in direct contact with the relatively cold coolingmedium, are preferably manufactured at least partially from plastic,since plastic can withstand relatively low temperatures relatively well,which will enhance the reliability and the durability of the dosingelement. If the relatively cold cooling medium comes into contact withmoisture (water) in uncontrolled manner, instantaneous freezing of themoisture will then generally occur, whereby ice (clump) formation willoccur. Since the dispensing opening of the dosing element is generallyin direct contact with the (moist) atmosphere, said effect will alsooccur here. The moisture condensed in the dispensing opening will freezeinstantaneously if cooling medium is dispensed by the dosing element viathe dispensing opening. The ice formation which will hereby occur willgenerally result in relatively rapid blockage of the dispensing opening.It is therefore recommended that the device comprises heating means forheating the dispensing opening. In this way condensation, and thereforefreezing and possible blockage of the dispensing opening, can beprevented.

Particularly in the case that the device is temporarily not in use thesupply conduit and the return conduit will warm up, whereby the coolingmedium present in the supply conduit and the return conduit will atleast partially evaporate. Before the device can be applied for thedispensing of a dosed quantity of cooling medium via the dosing elementthe supply conduit will first have to be degassed by flushing the supplyconduit with liquid cooling medium. The gas will herein be displacedinto the dosing compartment. Since the gaseous cooling medium has alower density than the liquid cooling medium, the gas in the dosingcompartment will displace as far as possible in upward direction. It istherefore advantageous when the supply conduit connects to the dosingcompartment, preferably via at least one feed opening, and the returnconduit connects to the dosing compartment, preferably via at least onereturn opening, wherein at least one return opening is located higherthan the at least one feed opening. By positioning the return openinghigher than the (uppermost) feed opening the gas collected in the dosingcompartment can be discharged relatively efficiently via the returnconduit. It is otherwise possible to envisage removing the gas generatedin the supply conduit from the device by means of other degassing means.The supply conduit itself and/or the dosing element can for instance beprovided for this purpose with a degassing mechanism.

The device according to the invention preferably comprises displacingmeans for displacing the cooling medium from the cooling medium supplycontainer to the dosing means. These displacing means and the drivingforce behind the displacement can be of very diverse nature here, thisbeing elucidated hereinbelow. In a particular preferred embodiment thedevice comprises at least one pump for pumping cooling medium throughthe cooling conduit. The pump, preferably a centrifugal pump, morepreferably a tail pump, is adapted to pump cooling medium through thesupply conduit at a predefined flow rate, this enhancing the eventualdosing of cooling medium by the dosing element. The flow rate of thepump can optionally be adjustable here. In another preferred embodimentthe device comprises at least one pump for pumping cooling mediumthrough the cooling conduit. The pump can also be formed here by a tailpump. It is otherwise possible here to envisage only a single pump beingapplied for the purpose of pumping cooling medium through both thesupply conduit and the cooling conduit, this being particularlyadvantageous in the case the supply conduit and the cooling conduitconnect to each other and therefore in fact form a single cooling mediumcircuit. It would also be possible to envisage positioning the coolingmedium supply container higher than the dosing element, whereby feed ofcooling medium to the dosing element could take place on the basis ofgravity, which could render the use of a pump unnecessary. Feed ofcooling medium to the dosing element solely on the basis of gravity willhowever generally make the dosing process more difficult because theflow rate through the supply conduit will generally not be(sufficiently) constant.

Applying a pump and/or gravitational forces for the purpose ofdisplacing cooling medium through the supply conduit and the coolingconduit has the further advantage that a so-called pressureless supplycontainer can be applied, i.e. a cooling medium supply container isapplied which is in open connection with an atmosphere surrounding thecooling medium supply container. The pressure in the cooling mediumsupply container is therefore substantially equal to the pressure of theatmosphere surrounding the cooling medium supply container. Such acooling medium supply container is generally substantially cheaper thana pressure vessel and is moreover relatively safe because no substantialpressure can and will build up in the cooling medium supply container,whereby it will be possible to eliminate the danger of the coolingmedium supply container exploding. Because cooling medium present in thecooling medium supply container will evaporate permanently, a permanentminimal overpressure will prevail in the cooling medium supplycontainer, whereby the open cooling medium supply container has aself-cleaning capability. It has moreover been found that cooling mediumcan be displaced from the cooling medium supply container to the atleast one dosing element in more rapid and therefore more effectivemanner by applying such a pressureless cooling medium supply containerthan if a pressure vessel were used. In addition, it has been found thatfilling of a pressureless vessel can take place (significantly) morequickly than filling of a pressurized cooling medium supply container(pressure vessel).

In an alternative preferred embodiment the cooling medium supplycontainer is formed by a pressure vessel, whereby flushing of the supplyconduit and the cooling conduit can take place by applying one or moreriser pipes arranged in the cooling medium supply container. Under theinfluence of the gas pressure built up in the cooling medium supplycontainer the cooling medium will then be forced through the supplyconduit and the cooling conduit via the at least one riser pipe. Asstated above however, a pressure vessel is relatively expensive andmoreover not wholly without risk, whereby a pressureless vessel willgenerally be preferred to a pressure vessel.

The invention also relates to a dosing element for use in a deviceaccording to the invention, wherein the dosing element comprises adosing compartment, which dosing compartment is provided with at leastone feed opening for feeding cooling medium to the dosing compartment,at least one return opening for discharging cooling medium from thedosing compartment, wherein at least one return opening is locatedhigher than the at least one feed opening. Advantages of the dosingelement and embodiment variants of the dosing element have already beendescribed at length in the foregoing.

In addition, the invention relates to an assembly of at least one supplyconduit and at least one cooling conduit at least partially enclosingthe at least one supply conduit for use in a device according to theinvention. The cooling conduit is preferably formed by a return conduitfor cooling medium coming from the supply conduit, whereby no additional(separate) cooling circuit is required for the purpose of cooling thesupply conduit by means of the cooling conduit. The supply conduit andthe cooling conduit are more preferably positioned substantiallycoaxially with each other. In a preferred embodiment the supply conduitand the cooling conduit are mutually connected via at least one dosingelement. The dosing element is preferably adapted here to at leastpartially or optionally completely block the passage from the supplyconduit to the cooling conduit. The dosing element will generally take amanipulable form here, wherein the dosing element is also adapted toleave clear the passage formed between the supply conduit and thecooling conduit in order to enable return of cooling medium. In aparticular preferred embodiment the supply conduit and the coolingconduit are manufactured at least partially from a substantiallyflexible material, preferably plastic, in particular Teflon®. The use offlexible materials facilitates the freedom of application of theassembly. The use of plastic is moreover advantageous because plastic isrelatively inexpensive and allows great freedom in design, and inaddition generally has a relatively low intrinsic heat capacity, wherebylosses of cold can be prevented as far as possible. Other advantages ofthe assembly and embodiment variants of the assembly have already beendescribed at length in the foregoing.

The invention further relates to a method for dosing cooling medium forthe purpose of cooling drinks by making use of a device according to theinvention, comprising the steps of: A) flushing the supply conduitduring a first period by causing liquid cooling medium to flow throughthe supply conduit, and B) causing a dosed quantity of cooling medium tobe dispensed by a dispensing opening forming part of the dosing elementduring a second period after the first period according to step A).Flushing of the supply conduit before causing a dosed quantity ofcooling medium to be dispensed is relevant in order to remove a possiblegas fraction from the supply conduit, whereby the subsequent dosing cantake place accurately and reliably. It is recommended here to at leastpartially discharge, via a return conduit, cooling medium guided intothe dosing element during step A), whereby the cooling medium removedfrom the supply conduit during flushing of the supply conduit can beefficiently reused. It is however also possible to envisage the coolingmedium guided into the dosing element during step A) being at leastpartially discharged via the dispensing opening of the dosing element inorder to enable degassing of the supply conduit. A quantity of liquidcooling medium possibly dispensed via the dispensing opening during stepA) can then be received in an empty drinking cup for the purpose ofbrief and effective pre-cooling of this drinking cup before drink isadded to the drinking cup. After filling of the drinking cup with drinka dosed quantity of cooling medium can then be supplied to the drinkingcup in controlled manner via the dispensing opening. It is advantageoushere that the dispensing opening is heated during step B), and morepreferably also during step A), to be able to counter ice formation inthe dispensing opening. The cooling medium is preferably pumped throughthe supply conduit during step A) and step B). Cooling medium can besupplied to the dosing element at a relatively constant flow rate(quantity per unit of time) by means of a pump, which considerablyfacilitates a time-controlled, precise dosing during step B).

The first period preferably amounts to between 2 and 15 seconds. Thiswill generally be sufficient for full degassing of the supply conduit,if necessary. The second period preferably amounts to between 1 and 10seconds. This will generally be sufficient to achieve an effective andsatisfactory cooling of a quantity of consumable beverage. The method,and thereby the device, are preferably controlled by a control unit,which control unit will generally be provided with one or more timersenabling at least steps A) and B) to be performed. The control unit willgenerally also be adapted to control the remaining part of thepreparation process, such as for instance the positioning of a drinkingcup below the dispensing opening and arranging of a dosed quantity ofdrink in the drinking cup. For a further specification hereof, referenceis made to the international patent application PCT/NL2008/050068, thecontent of which is deemed included in this patent specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of non-limitativeexemplary embodiments shown in the following figures. Herein:

FIG. 1 shows a schematic view of a vending machine provided with adevice according to the invention,

FIG. 2 shows a detailed cross-section of a dosing element for use in thedevice according to FIG. 1, and

FIGS. 3 a-3 f show views of different embodiment variants of a supplyconduit and a cooling conduit for use in a device according to theinvention.

DETAILED DESCRIPTION

FIG. 1 shows a schematic view of a vending machine 1 for serving cooledmilkshakes, which vending machine 1 is provided with a device 2 fordosing liquid nitrogen 3 for the purpose of cooling a milkshake. Device2 comprises for this purpose a pressureless supply container 4 partiallyfilled with nitrogen 3. Pressureless is understood to mean that supplycontainer 4 is in open connection with an atmosphere surrounding supplycontainer 4. Received in supply container 4 is a tail pump 5 which isconnected to a first dosing element 7 via a supply conduit 6. Supplyconduit 6 is coaxially enclosed by a return conduit 8 for nitrogen 3,this return conduit 8 being connected on one side to first dosingelement 7 and debouching on the other side in supply container 4. Device2 thus comprises one nitrogen circuit: liquid nitrogen 3 is pumped fromsupply container 4 into supply conduit 6 via tail pump 5 andsubsequently guided into return conduit 8 via first dosing element 7,after which the nitrogen 3 is fed back again into supply container 4.The purpose of applying return conduit 8 is to create a coolinginsulating sheath round supply conduit 6 in order to prevent evaporationof liquid nitrogen 3 in supply conduit 6. Evaporation of liquid nitrogen3 in supply conduit 6 would result in formation of gas in supply conduit6, which makes dosing of a predetermined quantity of liquid nitrogen 3by first dosing element 7 considerably more difficult. Before nitrogen 3is dosed using first dosing element 7 the supply conduit 6 is thereforefirst flushed with liquid nitrogen 3 in order to enable degassing ofsupply conduit 6. Gas possibly flushed out of supply conduit 6 will beguided back into supply container 4 via return conduit 8. After flushingof supply conduit 6 for a period of time the first dosing element 7 willbe operated to enable dispensing of a dosed quantity of nitrogen 3 to adrinking cup 10 via a dispensing opening 9. Before nitrogen 3 is addedto drinking cup 10, drinking cup 10 is first partially filled withmilkshake. For this purpose vending machine 1 comprises a supplycontainer 11 for milkshakes and a supply container 12 for an additive tobe added to the milkshake. Each of these supply containers 11, 12 iscoupled to a pump 13, 14 for supplying respectively milkshake andadditive to a second dosing element 15. Dosing element 15 is adapted toadd a dosed quantity of respectively milkshake and additive to drinkingcup 10. After adding of the milkshake enriched with the additive todrinking cup 10 a stirring element 16 will mix the milkshake and theadditive intensively with each other, wherein the dosed quantity ofnitrogen 3 will also be added to drinking cup 10 during the stirring.After cooling of the milkshake, it will be possible to remove drinkingcup 10 via a delivery compartment 17. Vending machine 2 comprises acontrol unit 18 for, among other purposes, time-controlled operation ofpumps 5, 13, 14, the two dosing elements 7, 15 and stirring element 16.Vending machine 2 further comprises a control panel 19 and a supplycontainer 20 for drinking cups 10.

FIG. 2 shows a detailed cross-section of first dosing element 7 for usein the device according to FIG. 1. As shown, dosing element 7 comprisesa dosing compartment 21 to which supply conduit 6, return conduit 8 anddispensing opening 9 connect. A plastic valve 22 is applied to enableclosure of dispensing opening 9 if desired. Valve 22 is here connectedvia a spacer 23 to an operating element 24, which is formed in thisexemplary embodiment by a magnet. The operating element, and therebyvalve 22, can be displaced by means of an electromagnet 25, wherebydispensing opening 9 can be closed or opened. The dispensing opening isprovided with a heating element 26 to prevent condensation andconsequent freezing in dispensing opening 9. As shown, the inlet toreturn conduit 8 is situated at a higher position than the outlet ofsupply conduit 6. In this way gas formed by evaporated nitrogen 3 andcoming from supply conduit 6 can be discharged relatively efficientlyvia return conduit 8.

FIGS. 3 a-3 f show views of different embodiment variants of a supplyconduit and a cooling conduit for use in a device according to theinvention. FIG. 3 a shows more particularly that a supply conduit 27 anda cooling conduit 28 can be oriented coaxially. FIG. 3 b shows that acooling conduit 29 only partly covers a periphery of an outer wall 30 ofa supply conduit 31. FIG. 3 c shows that a supply conduit 32 is enclosedby two cooling conduits 33 a, 33 b. FIG. 3 d shows that a curved supplyconduit 34 is received in a cooling conduit 35, which is in fact formedin this exemplary embodiment by a cooling reservoir through which flowoccurs. FIG. 3 e shows that a supply conduit 36 is fully enclosed by acooling conduit 37 in longitudinal direction. FIG. 3 f shows that asupply conduit 38 is partially enclosed by a cooling conduit 39 inlongitudinal direction. Supply conduit 38 and cooling conduit 39, morepreferably formed by a return conduit connected to supply conduit 38,are preferably manufactured from a substantially flexible material, inparticular plastic. A suitable plastic herein is Teflon(polytetrafluoroethylene (PTFE)). The advantage of applying a flexibleassembly of supply conduit 38 and cooling conduit 39 is that thisconsiderably facilitates the applicability of the assembly in general.At least the cooling conduit is preferably manufactured from a flexiblecorrugated pipe. The advantage of applying a corrugated pipe isgenerally that bending, and thereby blocking, of the cooling conduit canin this way be prevented.

It will be apparent that the invention is not limited to the exemplaryembodiments shown and described here but that numerous variants, whichwill be self evident to the skilled person in this field, are possiblewithin the scope of the appended claims.

1. Device for dosing a cooling medium, in particular for the purpose ofcooling drinks, comprising: at least one cooling medium supply containerfor holding at least one liquid cooling medium with a boiling pointlower than room temperature, at least one dosing element connected tothe cooling medium supply container via at least one supply conduit forthe purpose of dosing a quantity of liquid cooling medium, in particularfor cooling a drink by being mixed with the drink, and at least onecooling conduit connected to the cooling medium supply container forcooling with substantially liquid cooling medium the supply conduitprovided with cooling medium.
 2. Device as claimed in claim 1,characterized in that the cooling conduit connects to the supplyconduit.
 3. Device as claimed in claim 1 or 2, characterized in that thecooling conduit at least partially encloses the supply conduit. 4.Device as claimed in claim 3, characterized in that the cooling conduitsubstantially wholly encloses the supply conduit.
 5. Device as claimedin claim 3 or 4, characterized in that at least a part of the coolingconduit and at least a part of the supply conduit are oriented coaxiallywith each other.
 6. Device as claimed in any of the foregoing claims,characterized in that the cooling conduit is formed by a return conduitconnected to the supply conduit for the purpose of returning via thecooling conduit cooling medium guided through the supply conduit. 7.Device as claimed in claim 6, characterized in that the return conduitis connected to the supply conduit via the dosing element.
 8. Device asclaimed in claim 7, characterized in that the supply conduit and thereturn conduit connect to a dosing compartment forming part of thedosing element.
 9. Device as claimed in claim 8, characterized in thatthe supply conduit connects to the dosing compartment via at least onefeed opening, and that the return conduit connects to the dosingcompartment via at least one return opening, wherein at least one returnopening is located higher than the at least one feed opening.
 10. Deviceas claimed in any of the claims 7-9, characterized in that the dosingelement comprises at least one dispensing opening for cooling mediumconnecting to the supply conduit, and that the dosing element comprisesat least one controllable closing element for closing the dispensingopening of the supply conduit.
 11. Device as claimed in claim 10,characterized in that the device comprises heating means for heating thedispensing opening.
 12. Device as claimed in claim 10 or 11,characterized in that the closing element is connected to an operatingelement via at least one spacer for the purpose of enabling operation ofthe closing element at a distance from the closing element.
 13. Deviceas claimed in any of the foregoing claims, characterized in that thedevice comprises degassing means for degassing the supply conduit. 14.Device as claimed in any of the foregoing claims, characterized in thatthe device comprises at least one pump for pumping cooling mediumthrough the cooling conduit.
 15. Device as claimed in any of theforegoing claims, characterized in that the device comprises at leastone pump for pumping cooling medium through the supply conduit. 16.Device as claimed in any of the foregoing claims, characterized in thatthe cooling medium supply container is in open connection with theatmosphere.
 17. Device as claimed in any of the foregoing claims,characterized in that the cooling medium is formed by liquid nitrogen.18. Dosing element for use in a device as claimed in any of the claims1-17, characterized in that the dosing element comprises a dosingcompartment, which dosing compartment is provided with at least one feedopening for feeding cooling medium to the dosing compartment, at leastone return opening for discharging cooling medium from the dosingcompartment, wherein at least one return opening is located higher thanthe at least one feed opening.
 19. Assembly of at least one supplyconduit and at least one cooling conduit at least partially enclosingthe supply conduit for use in a device as claimed in any of the claims1-17.
 20. Assembly as claimed in claim 19, characterized in that thecooling conduit is formed by a return conduit for cooling medium comingfrom the supply conduit.
 21. Assembly as claimed in claim 19 or 20,characterized in that the supply conduit and the cooling conduit arepositioned substantially coaxially with each other.
 22. Assembly asclaimed in any of the claims 19-21, characterized in that the supplyconduit and the cooling conduit are mutually connected via at least onedosing element.
 23. Assembly as claimed in claim 22, characterized inthat the dosing element is adapted to at least partially block thepassage from the supply conduit to the cooling conduit.
 24. Assembly asclaimed in any of the claims 19-23, characterized in that the supplyconduit and the cooling conduit are manufactured at least partially froma substantially flexible material, preferably plastic, in particularTeflon.
 25. Method for dosing a cooling medium, particularly for thepurpose of cooling drinks, by making use of a device as claimed in anyof the claims 1-17, comprising the steps of: A) flushing the supplyconduit during a first period by causing substantially liquid coolingmedium with a boiling point lower than room temperature to flow throughthe supply conduit, and B) causing a dosed quantity of cooling medium tobe dispensed by a dispensing opening forming part of the dosing elementduring a second period after the first period according to step A). 26.Method as claimed in claim 25, characterized in that the substantiallyliquid cooling medium guided into the dosing element during step A) isat least partially discharged via a return conduit.
 27. Method asclaimed in claim 25 or 26, characterized in that the cooling mediumguided into the dosing element during step A) is at least partiallydischarged via the dispensing opening of the dosing element.
 28. Methodas claimed in any of the claims 25-27, characterized in that the coolingmedium is pumped through the supply conduit during step A) and step B).29. Method as claimed in any of the claims 25-28, characterized in thatthe dispensing opening is heated at least during step B).
 30. Method asclaimed in any of the claims 25-29, characterized in that the firstperiod amounts to between 2 and 15 seconds.
 31. Method as claimed in anyof the claims 25-30, characterized in that the second period amounts tobetween 1 and 10 seconds.